<form action="{site_url}/index.php?dn=article" method="post">
  <div class="form-search ac">
    <input name="sea" size="30" maxlength="20" value="" type="text" />
    <input name="re" value="search" type="hidden" />
    <button value="submit" class="sub"><span><em>{search}</em></span></button>
  </div>
</form>
<div class="clear">&nbsp;</div>